i66 THE SURGICAL ANATOMY OF THE HORSE 



by a small white band of ligamentous fibres which runs downwards and 

 forwards from the root of the ergot behind the fetlock to be attached 

 inferiorly to the retrossal process of the pedal bone. In appearance this 

 ligament of the ergot, as it is called, is very much like a nerve, and shows 

 quite a distinct longitudinal striation. It is somewhat broader and 

 flatter than the nerve, however, and a point to remember which will 

 materially assist in making the distinction is that the ligament is more 

 superficially placed, and that the nerve is accompanied in the same plane 

 by the vessels named, with which it may be found enclosed in the same 

 fibrous sheath. Notwithstanding what has been said, it is at times most 

 difficult to distinguish between them, and it is not by any means 

 uncommon that a student, when operating upon the dead limb at an 

 examination, removes a portion of the ligament in mistake for this 

 nerve. 



The complex arrangement of the various anatomical structures in 

 this region renders it most advisable that a thorough examination of the 

 dissected seat (Plate XXXIII.) should be made before the operation is 

 commenced. 



By adopting the following method the student will probably obtain 

 what is perhaps the best seat. Place a finger in the groove, and draw 

 it up the depression until the base of the sesamoid bone is felt. 

 The groove here suddenly seems to terminate, and it is at the upper 

 limit of the groove that the incision should be made. This will enable 

 the operator to keep clear of the ligament, since the latter crosses 

 the nerve and vessels at a slightly lower level. An oblique incision 

 should be made either downwards and forwards, or downwards and 

 backwards, so that when the lips of the incision are separated, the vein, 

 artery, and nerve may be exposed by dissection. Having done this, the 

 operation may be completed in the usual manner without much 

 difficulty. 



